Some Congestion control algorithms in the elementary transmission control protocol (TCP) based models such as TCP Reno [1]}, Tahoe [2]} and TCP Vegas [3]} have performed remarkably well. As current Internet scaled up by more than six times in size, speed and load in past few years. Hence, due to increased bandwidth delay, the model will eventually become a performance bottleneck. A new congestion control scheme, called FAST is developed by proposing an equation based algorithm to avoid packet level oscillation, using queuing delay as a measure of congestion and stable and weighed proportionally fair flow is obtained [4]}. Proportional fairness is achieved by their \( (p,1) \) -proportionally fair algorithm and max-min fairness is achieved as a limiting case of \( (p,\alpha ) \)  proportionally fairness. Mo et al. [5]} and La et al. [6]} proposed a window based algorithm, in which window sizes are adjusted more intelligently such that transmission rate and the backlog of packets should be controlled. TCP/AQM [7]} based optimization technique performs well under commonly defined constraints but it is hard to simulate in the current complex networks. Low et al. [8]} proposed a framework to cop up with buffer-bloat in multiple bottleneck links. The stability of the Controlled Delay (CoDel) is also analyzed and system stability and performance are improved by designing a self-tuning CoDel. In delay tolerant network (DTN), there is no guarantee of an end to end connection between source and destination hence, it is a challenging task to perform some functions like routing and congestion control. Aloizio et al. [9]} performed classification on existing DTN and provided a state of the art in DTN congestion control mechanisms. Giovanna et al. [10]} considered multi-path routing with joint congestion control and user throughput is maximized, and, overall network cost is minimized.
